The present invention relates to a map display system, which has a display screen capable of displaying maps and the like and is used in a vehicle navigation system.
Vehicle navigation systems use display devices capable of displaying maps and the like thereon. It is recently proposed to also provide internet information (HTML: hyper text markup language) in addition to the maps for travel route guidance. The navigation system is enabled to provide the HTML information, if a browser program for reading the HTML information is installed in the navigation system.
In installing the browser program in the navigation system, it is stored in a read only memory (ROM) provided in an electronic control circuit of the navigation system. When the browser program operates, a random access memory (RAM) provided in the control circuit is used. The browser program is generally so large that the ROM and the RAM, particularly VRAM, are required to be large enough in memory size. For this reason, additional ROMs and RAMs must be provided in the control circuit, resulting in a large-sized control circuit configuration.